Cooperative guidance problems of multiple missiles are considered in this article. A cooperative guidance scheme, where coordination algorithms and local guidance laws are combined together, is proposed. This scheme a...Cooperative guidance problems of multiple missiles are considered in this article. A cooperative guidance scheme, where coordination algorithms and local guidance laws are combined together, is proposed. This scheme actually builds up a hierarchical cooperative guidance architecture, which may provide a general solution to the multimissile cooperative guidance problems. In the case of salvo attacks which require missiles to hit the target simultaneously, both centralized and distributed coordination algorithms are derived based on the impact-time-control guidance （ITCG） law. Numerical simulations are performed to demonstrate the effectiveness of the proposed approaches.展开更多
Guidance problems with flight time constraints are considered in this article. A new virtual leader scheme is used for design of guidance laws with time constraints. The core idea of this scheme is to adopt a virtual ...Guidance problems with flight time constraints are considered in this article. A new virtual leader scheme is used for design of guidance laws with time constraints. The core idea of this scheme is to adopt a virtual leader for real missiles to convert a guidance problem with time constraints to a nonlinear tracking problem,thereby making it possible to settle the problem with a variety of control methods. A novel time-constrained guidance （TCG） law, which can control the flight time of missiles to a prescribed time,is designed by using the virtual leader scheme and stability method. The TCG law is a combination of the well-known proportional navigation guidance（PNG） law and the feedback of flight time error. What＇ s more, this law is free of singularities and hence yields better performances in comparison with optimal guidance laws with time constraints. Nonlinear simulations demonstrate the effectiveness of the proposed law.展开更多
Reconstruction of bone defects,especially the critical-sized defects,with mechanical integrity to the skeleton is important for a patient's rehabilitation,however,it still remains challenge.Utilizing biomaterials ...Reconstruction of bone defects,especially the critical-sized defects,with mechanical integrity to the skeleton is important for a patient's rehabilitation,however,it still remains challenge.Utilizing biomaterials of human origin bone tissue for therapeutic purposes has provided a facilitated approach that closely mimics the critical aspects of natural bone tissue with regard to its properties.However,not only efficacious and safe but also costeffective and convenient are important for regenerative biomaterials to achieve clinical translation and commercial success.Advances in our understanding of regenerative biomaterials and their roles in new bone formation potentially opened a new frontier in the fast-growing field of regenerative medicine.Taking inspiration from the role and multicomponent construction of native extracellular matrix(ECM)for cell accommodation,the ECM-mimicking biomaterials and the naturally decellularized ECM scaffolds were used to create new tissues for bone restoration.On the other hand,with the going deep in understanding of mesenchymal stem cells(MSCs),they have shown great promise to jumpstart and facilitate bone healing even in diseased microenvironments with pharmacology-based endogenous MSCs rescue/mobilization,systemic/local infusion of MSCs for cytotherapy,biomaterials-based approaches,cell-sheets/-aggregates technology and usage of subcellular vesicles of MSCs to achieve scaffolds-free or cell-free delivery system,all of them have been shown can improve MSCsmediated regeneration in preclinical studies and several clinical trials.Here,following an overview discussed autogenous/allogenic and ECM-based bone biomaterials for reconstructive surgery and applications of MSCsmediated bone healing and tissue engineering to further offer principles and effective strategies to optimize MSCs-based bone regeneration.展开更多
The scientific design and preliminary results of the data assimilation component of the Global-Regional Prediction and Assimilation System (GRAPES) recently developed in China Meteorological Administration (CMA) are p...The scientific design and preliminary results of the data assimilation component of the Global-Regional Prediction and Assimilation System (GRAPES) recently developed in China Meteorological Administration (CMA) are presented in this paper. This is a three-dimensional variational (3DVar) assimilation system set up on global and regional grid meshes favorable for direct assimilation of the space-based remote sensing data and matching the frame work of the prediction model GRAPES. The state variables are assumed to decompose balanced and unbalanced components. By introducing a simple transformation from the state variables to the control variables with a recursive or spectral filter, the convergence rate of iteration for minimization of the cost function in 3DVar is greatly accelerated. The definition of dynamical balance depends on the characteristic scale of the circulation considered. The ratio of the balanced to the unbalanced parts is controlled by the prescribed statistics of background errors. Idealized trials produce the same results as the analytic solution. The results of real data case studies show the capability of the system to improve analysis compared to the traditional schemes. Finally, further development of the system is discussed.展开更多
Cadmium(Cd)is a toxic heavy metal occurring in the environment naturally and is also generated through various anthropogenic sources and acts as a pollutant.Human health is affected by Cd pollution in farmland soils b...Cadmium(Cd)is a toxic heavy metal occurring in the environment naturally and is also generated through various anthropogenic sources and acts as a pollutant.Human health is affected by Cd pollution in farmland soils because food is the main source of Cd intake in the non-smoking population.For crops,Cd toxicity may result from a disturbance in uptake and translocation of mineral nutrients and disturbance in plant metabolism,inhibiting plant growth and development.However,plants have Cd tolerance mechanisms,including restricted Cd uptake,decreased Cd root-to-shoot translocation,enhanced antioxidant enzyme activities,and increased production of phytochelatins.Furthermore,optimal supply of mineral nutrients is one of the strategies to alleviate the damaging effects of Cd on plants and to avoid its entry into the food chain.The emerging molecular knowledge contributes to understanding Cd uptake,translocation,and remobilization in plants.In this review,Cd toxicity and tolerance mechanisms,agricultural practices to minimize Cd accumulation,Cd competition with essential elements(calcium,copper,iron,zinc,and manganese),and genes associated with Cd uptake are discussed in detail,especially regarding how these mineral nutrients and genes play a role in decreasing Cd uptake and accumulation in crop plants.展开更多
The worldwide incidence of bone disorders and conditions has been increasing. Bone is a nanomaterials composed of organic （mainly collagen） and inorganic （mainly nano-hydroxyapatite） components, with a hierarchica...The worldwide incidence of bone disorders and conditions has been increasing. Bone is a nanomaterials composed of organic （mainly collagen） and inorganic （mainly nano-hydroxyapatite） components, with a hierarchical structure ranging from nanoscale to macroscale. In consideration of the serious limitation in traditional therapies, nanomaterials provide some new strategy in bone regeneration. Nanostructured scaffolds provide a closer structural support approximation to native bone architecture for the cells and regulate cell proliferation, differentiation, and migration, which results in the formation of functional tissues. In this article, we focused on reviewing the classification and design of nanostructured materials and nanocarrier materials for bone regeneration, their cell interaction properties, and their application in bone tissue engineering and regeneration. Furthermore, some new challenges about the future research on the application of nanomaterials for bone regeneration are described in the conclusion and perspectives part.展开更多
The development of gastritis is associated with an increased risk of gastric cancer. Current invasive gastritis diagnostic methods are not suitable for monitoring progressIn this work based on 78 gastritis patients an...The development of gastritis is associated with an increased risk of gastric cancer. Current invasive gastritis diagnostic methods are not suitable for monitoring progressIn this work based on 78 gastritis patients and 50 healthy individuals, we observed that the variation of tongue-coating microbiota was associated with the occurrenee and development of gastritis. Twenty-one microbial species were identified for differentiating tongue-coating microbiomes of gastritis and healthy individuals. Pathways such as microbial metabolism in diverse environments, biosynthesis of antibiotics and bacterial chemotaxis were up-regulated in gastritis patients. The abundance of Campylobacter concisus was found associated with the gastric precancerous cascade. Furthermore, Campylobacter concisus could be detected in tongue coating and gastric fluid in a validation cohort containing 38 gastritis patients. These observations provided biological evidence of tongue diagnosis in traditional Chinese medicine, and indicated that tongue-coating microbiome could be a potential non-invasive biomarker, which might be suitable for long-term monitoring of gastritis.展开更多
In modern medicine,bone and dental loss and defects are common and widespread morbidities,for which regenerative therapy has shown great promise.Mesenchymal stem cells,obtained from various sources and playing an esse...In modern medicine,bone and dental loss and defects are common and widespread morbidities,for which regenerative therapy has shown great promise.Mesenchymal stem cells,obtained from various sources and playing an essential role in organ development and postnatal repair,have exhibited enormous potential for regenerating bone and dental tissue.Currently,mesenchymal stem cells (MSCs)-based bone and dental regeneration mainly includes two strategies: the rescue or mobilization of endogenous MSCs and the application of exogenous MSCs in cytotherapy or tissue engineering.Nevertheless,the efficacy of MSCbased regeneration is not always fulfilled,especially in diseased microenvironments.Specifically,the diseased microenvironment not only impairs the regenerative potential of resident MSCs but also controls the therapeutic efficacy of exogenous MSCs,both as donors and recipients.Accordingly,approaches targeting a diseased microenvironment have been established,including improving the diseased niche to restore endogenous MSCs,enhancing MSC resistance to a diseased microenvironment and renormalizing the microenvironment to guarantee MSC-mediated therapies.Moreover,the application of extracellular vesicles (EVs) as cell-free therapy has emerged as a promising therapeutic strategy.In this review,we summarize current knowledge regarding the tactics of MSC-based bone and dental regeneration and the decisive role of the microenvironment,emphasizing the therapeutic potential of microenvironment-targeting strategies in bone and dental regenerative medicine.展开更多
Iron homeostasis is essential for health;moreover,hepcidin-deficiency results in iron overload in both hereditary hemochromatosis and iron-loading anemia.Here,we identified iron modulators by functionally screening he...Iron homeostasis is essential for health;moreover,hepcidin-deficiency results in iron overload in both hereditary hemochromatosis and iron-loading anemia.Here,we identified iron modulators by functionally screening hepcidin agonists using a library of 640 FDA-approved drugs in human hepatic Huh7 cells.We validated the results in C57BL/6J mice and a mouse model of hemochromatosis(Hfe^(−/−)mice).Our screen revealed that the anti-rheumatoid arthritis drug auranofin(AUR)potently upregulates hepcidin expression.Interestingly,we found that canonical signaling pathways that regulate iron,including the Bmp/Smad and IL-6/Jak2/Stat3 pathways,play indispensable roles in mediating AUR’s effects.In addition,AUR induces IL-6 via the NF-κB pathway.In C57BL/6J mice,acute treatment with 5 mg/kg AUR activated hepatic IL-6/hepcidin signaling and decreased serum iron and transferrin saturation.Whereas chronically treating male Hfe^(−/−)mice with 5 mg/kg AUR activated hepatic IL-6/hepcidin signaling,decreasing systemic iron overload,but less effective in females.Further analyses revealed that estrogen reduced the ability of AUR to induce IL-6/hepcidin signaling in Huh7 cells,providing a mechanistic explanation for ineffectiveness of AUR in female Hfe^(−/−)mice.Notably,high-dose AUR(25 mg/kg)induces ferroptosis and causes lipid peroxidation through inhibition of thioredoxin reductase(TXNRD)activity.We demonstrate the ferroptosis inhibitor ferrostatin significantly protects liver toxicity induced by highdose AUR without comprising its beneficial effect on iron metabolism.In conclusion,our findings provide compelling evidence that TXNRD is a key regulator of ferroptosis,and AUR is a novel activator of hepcidin and ferroptosis via distinct mechanisms,suggesting a promising approach for treating hemochromatosis and hepcidin-deficiency related disorders.展开更多
OBJECTIVE： To investigate the apoptotic effects and underlying molecular mechanisms of Celastrus orbiculatus （C. orbiculatus） extract in human hepa- tocellular carcinoma cells. METHODS： Human hepatocellular carcin...OBJECTIVE： To investigate the apoptotic effects and underlying molecular mechanisms of Celastrus orbiculatus （C. orbiculatus） extract in human hepa- tocellular carcinoma cells. METHODS： Human hepatocellular carcinoma cells （HCCLM6） were treated with C. orbiculatus extract （COE） at different nontoxic concentrations （10, 20, 40, 80, and 160 IJg/mL）. The effect of COE on HC-CLM6 viability was examined using 3-（4,5-dimethyl- thiazol-2-yl）-2,5-diphenyl tetrazolium bromide （MTT） assays. Cellular apoptosis following COE treatment was assessed by flow cytometry and western blot analysis. RESULTS： COE significantly inhibited cell viability and induced apoptosis of HCCLM6 cells in a dose-dependent manner. Apoptosis was accompa- nied by increased Bax expression and decreased Bcl-2 expression. In addition, COE treatment led to the release of cytochrome c, activation of cas- pase-3, and cleavage of poly （ADP-ribose） poly- merase （PARP）. Furthermore, activation of extracel- lular signal-regulated kinase （ERK）, p38 kinase, and c-Jun N-terminal kinase （JNK） phosphorylation, and down-regulation of Akt phosphorylation was ob- served. CONCLUSION： COE induces mitochondrial-mediat- ed, caspase-dependent apoptosis in HCCLM6 cells, which might be attributed to the activation of mito- gen-activated protein kinase （MAPK） and inhibition of Akt signaling pathways. These data suggest that COE may be a potential treatment for human hepa- tocellular carcinoma.展开更多
Artemisia annua is the major natural source of artemisinin,an anti-malarial medicine commonly used worldwide.Here,we present chromosome-level haploid maps for two A.annua strains with different artemisinin contents to...Artemisia annua is the major natural source of artemisinin,an anti-malarial medicine commonly used worldwide.Here,we present chromosome-level haploid maps for two A.annua strains with different artemisinin contents to explore the relationships between genomic organization and artemisinin production.High-fidelity sequencing,optical mapping,and chromatin conformation capture sequencing were used to assemble the heterogeneous and repetitive genome and resolve the haplotypes of A.annua.Approximately 5o,ooo genes were annotated for each haplotype genome,and a triplication event that occurred approximately 58.12million years ago was examined for the first time in this species.A total of 3,903,467-5,193,414 variants(SNPs,indels,and structural variants)were identified in the 1.5-Gb genome during pairwise comparison between haplotypes,consistent with the high heterozygosity of this species.Genomic analyses revealed a correlation between artemisinin concents and the copy number of amorpha-4,11-dienes ynthasegenes.This correlation was further confirmed by resequencing of 36A.annua samples with varied artemisinin contents.Circular consensus sequencing of transcripts facilitated the detection of paralog expression.Collectively,our study provides chromosome-level allele-aware genome assemblies for two A.annua strains and new insights into the biosynthesis of artemisinin and its regulation,which will contribute to conquering malaria worldwide.展开更多
High grain protein content(GPC) reduces rice eating and cooking quality(ECQ). We generated OsAAP6 and OsAAP10 knockout mutants in three high-yielding japonica varieties and one japonica line using the CRISPR/Cas9 syst...High grain protein content(GPC) reduces rice eating and cooking quality(ECQ). We generated OsAAP6 and OsAAP10 knockout mutants in three high-yielding japonica varieties and one japonica line using the CRISPR/Cas9 system. Mutation efficiency varied with genetic background in the T_0 generation, and GPC in the T_1 generation decreased significantly,owing mainly to a reduction in glutelin content. Amylose content was down-regulated significantly in some Osaap6 and all Osaap10 mutants. The increased taste value of these mutants was supported by Rapid Visco Analysis(RVA) profiles, which showed higher peak viscosity and breakdown viscosity and lower setback viscosity than the wild type. There were no significant deficiencies in agronomic traits of the mutants. Targeted mutagenesis of OsAAP6 and OsAAP10, especially OsAAP10, using the CRISPR/Cas9 system can rapidly reduce GPC and improve ECQ of rice, providing a new strategy for the breeding cultivars with desired ECQ.展开更多
Prehospital delay is one of the major causes of low rate of intravenous recombinant tissue plasminogen activator(rt-PA)thrombolysis for acute ischaemic stroke in China.Regional emergency systems have been proven a suc...Prehospital delay is one of the major causes of low rate of intravenous recombinant tissue plasminogen activator(rt-PA)thrombolysis for acute ischaemic stroke in China.Regional emergency systems have been proven a successful approach to improve access to thrombolysis.Shenzhen is a high population density city with great geographical disparity of healthcare resources,leading to limited access to rt-PA thrombolysis for most patients with acute ischaemic stroke.To improve rapid access to rt-PA thrombolysis in Shenzhen,a Shenzhen stroke emergency map was implemented by Shenzhen healthcare administrations.This map comprised certification of qualified local hospitals,identification of patients with stroke,acute stroke transport protocol and maintenance of the map.We conducted a retrospective observational study to compare consecutive patients with acute stroke arriving at qualified local hospitals before and after implementation of the Shenzhen stroke emergency map.After implementation of the map,the rate of patients receiving rt-PA thrombolysis increased from 8.3%to 9.7%(p=0.003),and the rate of patients treated with endovascular thrombectomy increased from 0.9%to 1.6%(p<0.001).Sixteen of 20 hospitals have an increase in the number of patients with stroke treated with rt-PA thrombolysis.The median time between receipt of the call and arrival on the scene reduced significantly(17.0 min vs 9.0 min,p<0.001).In Shenzhen Second People's Hospital,the median onset-to-needle time and door-to-needle time were reduced(175.5 min vs 149.5 min,p=0.039;71.5 min vs 51.5 min,p<0.001).No statistically significant differences were found in the proportion of rt-PA-treated patients within various geographical distances.Currently,there are more than 40 cities in China implementing a stroke emergency map.The Shenzhen stroke emergency map improves access to rt-PA thrombolysis for acute ischaemic stroke,and the novel model has been expanded to multiple areas in China.Future efforts should be conducted to optimise the stroke emergency map.展开更多
Background:Resistance to ferroptosis,a regulated cell death caused by irondependent excessive accumulation of lipid peroxides,has recently been linked to lung adenocarcinoma(LUAD).Intracellular antioxidant systems are...Background:Resistance to ferroptosis,a regulated cell death caused by irondependent excessive accumulation of lipid peroxides,has recently been linked to lung adenocarcinoma(LUAD).Intracellular antioxidant systems are required for protection against ferroptosis.The purpose of the present studywas to investigate whether and how extracellular system desensitizes LUAD cells to ferroptosis.Methods:Established human lung fibroblasts MRC-5,WI38,and human LUAD H1650,PC9,H1975,H358,A549,and H1299 cell lines,tumor and matched normal adjacent tissues of LUAD,and plasma from healthy individuals and LUAD patients were used in this study.Immunohistochemistry and immunoblotting were used to analyze protein expression,and quantitative reverse transcription-PCR was used to analyze mRNA expression.Cell viability,cell death,and the lipid reactive oxygen species generationwere measured to evaluate the responses to ferroptosis.Exosomes were observed using transmission electron microscope.The localization of arachidonic acid(AA)was detected using click chemistry labeling followed by confocal microscopy.Interactions between RNAs and proteins were detected using RNA pull-down,RNA immunoprecipitation and photoactivatable ribonucleoside-enhanced crosslinking and immunoprecipitation methods.Proteomic analysis was used to investigate RNA-regulated proteins,and metabolomic analysis was performed to analyze metabolites.Cellderived xenograft,patient-derived xenograft,cell-implanted intrapulmonary LUAD mouse models and plasma/tissue specimens from LUAD patients were used to validate the molecular mechanism.Results:Plasma exosome from LUAD patients specifically reduced lipid peroxidation and desensitized LUAD cells to ferroptosis.A potential explanation is that exosomal circRNA_101093(cir93)maintained an elevation in intracellular cir93 in LUAD to modulate AA,a poly-unsaturated fatty acid critical for ferroptosisassociated increased peroxidation in the plasma membrane.Mechanistically,cir93 interacted with and increased fatty acid-binding protei展开更多
Metal–organic frameworks(MOFs) are of great interest as potential electrochemically active materials.However, few studies have been conducted into understanding whether control of the shape and components of MOFs can...Metal–organic frameworks(MOFs) are of great interest as potential electrochemically active materials.However, few studies have been conducted into understanding whether control of the shape and components of MOFs can optimize their electrochemical performances due to the rational realization of their shapes. Component control of MOFs remains a significant challenge. Herein, we demonstrate a solvothermal method to realize nanostructure engineering of 2D nanoflake MOFs. The hollow structures withNi/Co-and Ni-MOF(denoted as Ni/Co-MOF nanoflakes and Ni-MOF nanoflakes) were assembled for their electrochemical performance optimizations in supercapacitors and in the oxygen reduction reaction(ORR). As a result, the Ni/CoMOF nanoflakes exhibited remarkably enhanced performance with a specific capacitance of 530.4 F g^(-1)at 0.5 A g^(-1)in1 M LiO H aqueous solution, much higher than that of NiMOF(306.8 F g^(-1)) and ZIF-67(168.3 F g^(-1)), a good rate capability, and a robust cycling performance with no capacity fading after 2000 cycles. Ni/Co-MOF nanoflakes also showed improved electrocatalytic performance for the ORR compared to Ni-MOF and ZIF-67. The present work highlights the significant role of tuning 2D nanoflake ensembles of Ni/Co-MOF in accelerating electron and charge transportation for optimizing energy storage and conversion devices.展开更多
Fuel tank inerting technologies are able to reduce the fire risk by injection of inert gas into the ullage or fuel, the former called ullage washing and the latter fuel scrubbing. The Green On-Board Inert Gas Generati...Fuel tank inerting technologies are able to reduce the fire risk by injection of inert gas into the ullage or fuel, the former called ullage washing and the latter fuel scrubbing. The Green On-Board Inert Gas Generation System（GOBIGGS） is a novel technology based on flameless catalytic combustion, and owning to its simple structure and high inerting efficiency, it has received a lot of attentions. The inert gas in the GOBIGGS is mainly comprised of CO2, N2, and O2（hereinafter, Mixed Inert Gas（MIG））, while that in the On-Board Inert Gas Generation System（OBIGGS）, which is one of the most widely used fuel tank inerting technologies, is NitrogenEnriched Air（NEA）. The solubility of CO2 is nearly 20 times higher than that of N2 in jet fuels,so the inerting capability and performance are definitely disparate if the inert gas is selected as NEA or MIG. An inerting test bench was constructed to compare the inerting capabilities between NEA and MIG. Experimental results reveal that, if ullage washing is adopted, the variations of oxygen concentrations on the ullage and in the fuel are nearly identical no matter the inert gas is NEA or MIG. However, the ullage and dissolved oxygen concentrations of MIG scrubbing are always higher than those of NEA scrubbing.展开更多
Osteoarthritis, a disorder characterized by articular cartilage deterioration, varying degrees of inflammation, and chondrocyte apoptosis, is the most common chronic joint disease. To slow or reverse its progression, ...Osteoarthritis, a disorder characterized by articular cartilage deterioration, varying degrees of inflammation, and chondrocyte apoptosis, is the most common chronic joint disease. To slow or reverse its progression, inflammation should be inhibited, and chondrocyte proliferation should be promoted. Tetrahedral framework nucleic acids can be internalized by chondrocytes(even inflammatory chondrocytes) and can enhance their proliferation and migration. Wogonin, a naturally occurring flavonoid,suppresses oxidative stress and inhibits inflammation. In this study, tetrahedral framework nucleic acids were successfully selfassembled and used to load wogonin. We confirmed the effective formation of tetrahedral framework nucleic acid/wogonin complexes by dynamic light scattering, zeta potential analysis, transmission electron microscopy, and fluorescence spectrophotometry. Tetrahedral framework nucleic acids, wogonin, and especially tetrahedral framework nucleic acid/wogonin complexes effectively alleviated inflammation in vitro and in vivo and prevented cartilage destruction. In addition, these materials remarkably downregulated the expression of inflammatory mediators and matrix metalloproteinases, upregulated chondrogenic markers, and promoted tissue inhibitor of metalloproteinase 1 and B-cell lymphoma 2 expression. In vivo, after treatment with tetrahedral framework nucleic acid/wogonin complexes, the bone mineral density in regenerated tissues was much higher than that found in the untreated groups. Histologically, the complexes enhanced new tissue regeneration, significantly suppressed chondrocyte apoptosis, and promoted chondrogenic marker expression. They also inhibited cell apoptosis, increased chondrogenic marker expression, and suppressed the expression of inflammatory mediators in osteoarthritis. Therefore, we believe that tetrahedral framework nucleic acid/wogonin complexes can be used as an injectable form of therapy for osteoarthritis.展开更多
Magnesium(Mg)affects various critical physiological and biochemical processes in higher plants,and its deficiency impedes plant growth and development.Although potassium(K)-induced Mg deficiency in agricultural produc...Magnesium(Mg)affects various critical physiological and biochemical processes in higher plants,and its deficiency impedes plant growth and development.Although potassium(K)-induced Mg deficiency in agricultural production is widespread,the specific relationship of K with Mg and especially its competitive nature is poorly understood.This review summarizes current knowledge on the interactions between K and Mg with respect to their root uptake,root-to-shoot translocation and distribution in plants.Their synergistic effects on certain physiological functions are also described.The antagonistic effect of K on Mg is stronger than that of Mg on K in root absorption and transport within plants,indicating that the balanced use of K and Mg fertilizers is necessary for sustaining high plant-available Mg and alleviating K-induced Mg deficiency,especially in plant species with high K demand or in highavailable-K soil.The relationship between Mg and K in plant tissues may be antagonistic or synergistic depending on plant species,cell type,leaf age,source-and sink organs.There are synergistic effects of K and Mg on photosynthesis,carbohydrate transport and allocation,nitrogen metabolism,and turgor regulation.Definition of optimal K/Mg ratios for soils and plant tissues is desirable for maintaining proper nutritional status in plants,leading to a physiological state supporting crop production.Future research should concentrate on identifying the physiological and molecular mechanisms underlying the interactions between K and Mg in a given physiological function.展开更多
Copper is an indispensable trace metal element in the human body,which is mainly absorbed in the stomach and small intestine and excreted into the bile.Copper is an important component and catalytic agent of many enzy...Copper is an indispensable trace metal element in the human body,which is mainly absorbed in the stomach and small intestine and excreted into the bile.Copper is an important component and catalytic agent of many enzymes and proteins in the body,so it can influence human health through multiple mechanisms.Based on the biological functions and benefits of copper,an increasing number of researchers in the field of biomaterials have focused on developing novel copper-containing biomaterials,which exhibit unique properties in protecting the cardiovascular system,promoting bone fracture healing,and exerting antibacterial effects.Copper can also be used in promoting incisional wounds healing,killing cancer cells,Positron Emission Tomography(PET)imaging,radioimmunological tracing and radiotherapy of cancer.In the present review,the biological functions of copper in the human body are presented,along with an overview of recent progress in our understanding of the biological applications and development of copper-containing materials.Furthermore,this review also provides the prospective on the challenges of those novel biomaterials for future clinical applications.展开更多
基金Foundation items： National Natural Science Foundation of China （60674103） Aeronautical Science Foundation of China （2006ZC51026）
文摘Cooperative guidance problems of multiple missiles are considered in this article. A cooperative guidance scheme, where coordination algorithms and local guidance laws are combined together, is proposed. This scheme actually builds up a hierarchical cooperative guidance architecture, which may provide a general solution to the multimissile cooperative guidance problems. In the case of salvo attacks which require missiles to hit the target simultaneously, both centralized and distributed coordination algorithms are derived based on the impact-time-control guidance （ITCG） law. Numerical simulations are performed to demonstrate the effectiveness of the proposed approaches.
基金National Natural Science Foundation of China(60674103,60975073)National High-tech Research and Develop-ment Program of China (2006AA04Z260)+1 种基金Research Foundation forDoctoral Program of Higher Education of China (20091102110006 )Aeronautical Science Foundation of China(2008ZC13011)
文摘Guidance problems with flight time constraints are considered in this article. A new virtual leader scheme is used for design of guidance laws with time constraints. The core idea of this scheme is to adopt a virtual leader for real missiles to convert a guidance problem with time constraints to a nonlinear tracking problem,thereby making it possible to settle the problem with a variety of control methods. A novel time-constrained guidance （TCG） law, which can control the flight time of missiles to a prescribed time,is designed by using the virtual leader scheme and stability method. The TCG law is a combination of the well-known proportional navigation guidance（PNG） law and the feedback of flight time error. What＇ s more, this law is free of singularities and hence yields better performances in comparison with optimal guidance laws with time constraints. Nonlinear simulations demonstrate the effectiveness of the proposed law.
基金supported by the National Key Research and Development Program of China(2016YFC1101400)the National Natural Science Foundation of China(No.81930025,81620108007,81901010)Open Foundation of Shandong Provincial Key Laboratory of Oral Tissue Regeneration(No.SDKQ201904).
文摘Reconstruction of bone defects,especially the critical-sized defects,with mechanical integrity to the skeleton is important for a patient's rehabilitation,however,it still remains challenge.Utilizing biomaterials of human origin bone tissue for therapeutic purposes has provided a facilitated approach that closely mimics the critical aspects of natural bone tissue with regard to its properties.However,not only efficacious and safe but also costeffective and convenient are important for regenerative biomaterials to achieve clinical translation and commercial success.Advances in our understanding of regenerative biomaterials and their roles in new bone formation potentially opened a new frontier in the fast-growing field of regenerative medicine.Taking inspiration from the role and multicomponent construction of native extracellular matrix(ECM)for cell accommodation,the ECM-mimicking biomaterials and the naturally decellularized ECM scaffolds were used to create new tissues for bone restoration.On the other hand,with the going deep in understanding of mesenchymal stem cells(MSCs),they have shown great promise to jumpstart and facilitate bone healing even in diseased microenvironments with pharmacology-based endogenous MSCs rescue/mobilization,systemic/local infusion of MSCs for cytotherapy,biomaterials-based approaches,cell-sheets/-aggregates technology and usage of subcellular vesicles of MSCs to achieve scaffolds-free or cell-free delivery system,all of them have been shown can improve MSCsmediated regeneration in preclinical studies and several clinical trials.Here,following an overview discussed autogenous/allogenic and ECM-based bone biomaterials for reconstructive surgery and applications of MSCsmediated bone healing and tissue engineering to further offer principles and effective strategies to optimize MSCs-based bone regeneration.
基金Key Technologies Research and Development Program (Grant No. 2001BA607B and 2001BA607B02)National Natural Science Foundation of China (Grant No. 40518001)
文摘The scientific design and preliminary results of the data assimilation component of the Global-Regional Prediction and Assimilation System (GRAPES) recently developed in China Meteorological Administration (CMA) are presented in this paper. This is a three-dimensional variational (3DVar) assimilation system set up on global and regional grid meshes favorable for direct assimilation of the space-based remote sensing data and matching the frame work of the prediction model GRAPES. The state variables are assumed to decompose balanced and unbalanced components. By introducing a simple transformation from the state variables to the control variables with a recursive or spectral filter, the convergence rate of iteration for minimization of the cost function in 3DVar is greatly accelerated. The definition of dynamical balance depends on the characteristic scale of the circulation considered. The ratio of the balanced to the unbalanced parts is controlled by the prescribed statistics of background errors. Idealized trials produce the same results as the analytic solution. The results of real data case studies show the capability of the system to improve analysis compared to the traditional schemes. Finally, further development of the system is discussed.
基金supported by the Science and Technology Innovation Fund of Henan Agricultural University,China(No.KJCX2019A19)the National Key R&D Program of China(No.2017YFD0201700)the Doctoral Scientific Research Foundation of Henan Agricultural University,China(No.30500592)。
文摘Cadmium(Cd)is a toxic heavy metal occurring in the environment naturally and is also generated through various anthropogenic sources and acts as a pollutant.Human health is affected by Cd pollution in farmland soils because food is the main source of Cd intake in the non-smoking population.For crops,Cd toxicity may result from a disturbance in uptake and translocation of mineral nutrients and disturbance in plant metabolism,inhibiting plant growth and development.However,plants have Cd tolerance mechanisms,including restricted Cd uptake,decreased Cd root-to-shoot translocation,enhanced antioxidant enzyme activities,and increased production of phytochelatins.Furthermore,optimal supply of mineral nutrients is one of the strategies to alleviate the damaging effects of Cd on plants and to avoid its entry into the food chain.The emerging molecular knowledge contributes to understanding Cd uptake,translocation,and remobilization in plants.In this review,Cd toxicity and tolerance mechanisms,agricultural practices to minimize Cd accumulation,Cd competition with essential elements(calcium,copper,iron,zinc,and manganese),and genes associated with Cd uptake are discussed in detail,especially regarding how these mineral nutrients and genes play a role in decreasing Cd uptake and accumulation in crop plants.
基金funded by Funding of National Natural Science Foundation of China (81470721, 31170929, 81321002)Sichuan Science and Technology Innovation Team (2014TD0001)
文摘The worldwide incidence of bone disorders and conditions has been increasing. Bone is a nanomaterials composed of organic （mainly collagen） and inorganic （mainly nano-hydroxyapatite） components, with a hierarchical structure ranging from nanoscale to macroscale. In consideration of the serious limitation in traditional therapies, nanomaterials provide some new strategy in bone regeneration. Nanostructured scaffolds provide a closer structural support approximation to native bone architecture for the cells and regulate cell proliferation, differentiation, and migration, which results in the formation of functional tissues. In this article, we focused on reviewing the classification and design of nanostructured materials and nanocarrier materials for bone regeneration, their cell interaction properties, and their application in bone tissue engineering and regeneration. Furthermore, some new challenges about the future research on the application of nanomaterials for bone regeneration are described in the conclusion and perspectives part.
基金National Natural Science Foundation of China (Grant Nos. 81630103, 91729301, 91229201 and 81225025)the Project of Tsinghua-Fuzhou Insititute for Data Technology (TFIDT2018001)to S. Li and grants 61673231 and 61721003 to X. Zhang.
文摘The development of gastritis is associated with an increased risk of gastric cancer. Current invasive gastritis diagnostic methods are not suitable for monitoring progressIn this work based on 78 gastritis patients and 50 healthy individuals, we observed that the variation of tongue-coating microbiota was associated with the occurrenee and development of gastritis. Twenty-one microbial species were identified for differentiating tongue-coating microbiomes of gastritis and healthy individuals. Pathways such as microbial metabolism in diverse environments, biosynthesis of antibiotics and bacterial chemotaxis were up-regulated in gastritis patients. The abundance of Campylobacter concisus was found associated with the gastric precancerous cascade. Furthermore, Campylobacter concisus could be detected in tongue coating and gastric fluid in a validation cohort containing 38 gastritis patients. These observations provided biological evidence of tongue diagnosis in traditional Chinese medicine, and indicated that tongue-coating microbiome could be a potential non-invasive biomarker, which might be suitable for long-term monitoring of gastritis.
基金supported by the National Key Research and Development Program of China (2016YFC1101400 to Y.J.)the National Natural Science Foundation of China (31800817 to S.L., 31870970 to J.Z.)
文摘In modern medicine,bone and dental loss and defects are common and widespread morbidities,for which regenerative therapy has shown great promise.Mesenchymal stem cells,obtained from various sources and playing an essential role in organ development and postnatal repair,have exhibited enormous potential for regenerating bone and dental tissue.Currently,mesenchymal stem cells (MSCs)-based bone and dental regeneration mainly includes two strategies: the rescue or mobilization of endogenous MSCs and the application of exogenous MSCs in cytotherapy or tissue engineering.Nevertheless,the efficacy of MSCbased regeneration is not always fulfilled,especially in diseased microenvironments.Specifically,the diseased microenvironment not only impairs the regenerative potential of resident MSCs but also controls the therapeutic efficacy of exogenous MSCs,both as donors and recipients.Accordingly,approaches targeting a diseased microenvironment have been established,including improving the diseased niche to restore endogenous MSCs,enhancing MSC resistance to a diseased microenvironment and renormalizing the microenvironment to guarantee MSC-mediated therapies.Moreover,the application of extracellular vesicles (EVs) as cell-free therapy has emerged as a promising therapeutic strategy.In this review,we summarize current knowledge regarding the tactics of MSC-based bone and dental regeneration and the decisive role of the microenvironment,emphasizing the therapeutic potential of microenvironment-targeting strategies in bone and dental regenerative medicine.
基金supported by research grants from the National Natural Science Foundation of China(31530034 and 31930057 to F.W.,31570791 to J.M.,31701035 to H.W.,31701034 to Q.W.,and 81500984 to L.Y.)the National Key Research and Development Program of China(2018YFA0507802 to F.W.,2018YFA0507801 to J.M.).
文摘Iron homeostasis is essential for health;moreover,hepcidin-deficiency results in iron overload in both hereditary hemochromatosis and iron-loading anemia.Here,we identified iron modulators by functionally screening hepcidin agonists using a library of 640 FDA-approved drugs in human hepatic Huh7 cells.We validated the results in C57BL/6J mice and a mouse model of hemochromatosis(Hfe^(−/−)mice).Our screen revealed that the anti-rheumatoid arthritis drug auranofin(AUR)potently upregulates hepcidin expression.Interestingly,we found that canonical signaling pathways that regulate iron,including the Bmp/Smad and IL-6/Jak2/Stat3 pathways,play indispensable roles in mediating AUR’s effects.In addition,AUR induces IL-6 via the NF-κB pathway.In C57BL/6J mice,acute treatment with 5 mg/kg AUR activated hepatic IL-6/hepcidin signaling and decreased serum iron and transferrin saturation.Whereas chronically treating male Hfe^(−/−)mice with 5 mg/kg AUR activated hepatic IL-6/hepcidin signaling,decreasing systemic iron overload,but less effective in females.Further analyses revealed that estrogen reduced the ability of AUR to induce IL-6/hepcidin signaling in Huh7 cells,providing a mechanistic explanation for ineffectiveness of AUR in female Hfe^(−/−)mice.Notably,high-dose AUR(25 mg/kg)induces ferroptosis and causes lipid peroxidation through inhibition of thioredoxin reductase(TXNRD)activity.We demonstrate the ferroptosis inhibitor ferrostatin significantly protects liver toxicity induced by highdose AUR without comprising its beneficial effect on iron metabolism.In conclusion,our findings provide compelling evidence that TXNRD is a key regulator of ferroptosis,and AUR is a novel activator of hepcidin and ferroptosis via distinct mechanisms,suggesting a promising approach for treating hemochromatosis and hepcidin-deficiency related disorders.
基金Supported by the National Natural Science Foundation of China(No.81173603 and No.81274141)State Administration of Traditional Chinese Medicine of China(No.0405ZP35)+3 种基金Jiangsu Provincial Social Development Project(No. BE2011738)the Natural Science Foundation of Jiangsu Province(No.BK2012686)Administration of Traditional Chinese Medicine of Jiangsu Province(No.LZ11210)and the Project of Cooperation between Yangzhou University and Yangzhou City(No.YZ2010157)
文摘OBJECTIVE： To investigate the apoptotic effects and underlying molecular mechanisms of Celastrus orbiculatus （C. orbiculatus） extract in human hepa- tocellular carcinoma cells. METHODS： Human hepatocellular carcinoma cells （HCCLM6） were treated with C. orbiculatus extract （COE） at different nontoxic concentrations （10, 20, 40, 80, and 160 IJg/mL）. The effect of COE on HC-CLM6 viability was examined using 3-（4,5-dimethyl- thiazol-2-yl）-2,5-diphenyl tetrazolium bromide （MTT） assays. Cellular apoptosis following COE treatment was assessed by flow cytometry and western blot analysis. RESULTS： COE significantly inhibited cell viability and induced apoptosis of HCCLM6 cells in a dose-dependent manner. Apoptosis was accompa- nied by increased Bax expression and decreased Bcl-2 expression. In addition, COE treatment led to the release of cytochrome c, activation of cas- pase-3, and cleavage of poly （ADP-ribose） poly- merase （PARP）. Furthermore, activation of extracel- lular signal-regulated kinase （ERK）, p38 kinase, and c-Jun N-terminal kinase （JNK） phosphorylation, and down-regulation of Akt phosphorylation was ob- served. CONCLUSION： COE induces mitochondrial-mediat- ed, caspase-dependent apoptosis in HCCLM6 cells, which might be attributed to the activation of mito- gen-activated protein kinase （MAPK） and inhibition of Akt signaling pathways. These data suggest that COE may be a potential treatment for human hepa- tocellular carcinoma.
基金This work was supported by the National Key R&D Program of China(2019YFC1711100)the National Natural Science Foundation of China(U1812403-1,81641002)+1 种基金the Fundamental Research Funds forthe Central Public Welfare Research Institutes(ZZ13-YQ-047,ZZ13-YQ-102)the National Major Science and Technology Projects(2017ZX09101002-003-001,2019ZX09201005-006-001,2019ZX09201005-002-002).
文摘Artemisia annua is the major natural source of artemisinin,an anti-malarial medicine commonly used worldwide.Here,we present chromosome-level haploid maps for two A.annua strains with different artemisinin contents to explore the relationships between genomic organization and artemisinin production.High-fidelity sequencing,optical mapping,and chromatin conformation capture sequencing were used to assemble the heterogeneous and repetitive genome and resolve the haplotypes of A.annua.Approximately 5o,ooo genes were annotated for each haplotype genome,and a triplication event that occurred approximately 58.12million years ago was examined for the first time in this species.A total of 3,903,467-5,193,414 variants(SNPs,indels,and structural variants)were identified in the 1.5-Gb genome during pairwise comparison between haplotypes,consistent with the high heterozygosity of this species.Genomic analyses revealed a correlation between artemisinin concents and the copy number of amorpha-4,11-dienes ynthasegenes.This correlation was further confirmed by resequencing of 36A.annua samples with varied artemisinin contents.Circular consensus sequencing of transcripts facilitated the detection of paralog expression.Collectively,our study provides chromosome-level allele-aware genome assemblies for two A.annua strains and new insights into the biosynthesis of artemisinin and its regulation,which will contribute to conquering malaria worldwide.
基金financially supported by National Key Research and Development Program of China(2016YFD0100501)the National Natural Science Foundation of China(31871241,31371233)+3 种基金the Natural Science Foundation of Jiangsu Province(BE2017345,PZCZ201702,BE2018351)the Research and Innovation Program of Postgraduate in Jiangsu Province(KYCX17_1886)the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Yangzhou University International Academic Exchange Fund。
文摘High grain protein content(GPC) reduces rice eating and cooking quality(ECQ). We generated OsAAP6 and OsAAP10 knockout mutants in three high-yielding japonica varieties and one japonica line using the CRISPR/Cas9 system. Mutation efficiency varied with genetic background in the T_0 generation, and GPC in the T_1 generation decreased significantly,owing mainly to a reduction in glutelin content. Amylose content was down-regulated significantly in some Osaap6 and all Osaap10 mutants. The increased taste value of these mutants was supported by Rapid Visco Analysis(RVA) profiles, which showed higher peak viscosity and breakdown viscosity and lower setback viscosity than the wild type. There were no significant deficiencies in agronomic traits of the mutants. Targeted mutagenesis of OsAAP6 and OsAAP10, especially OsAAP10, using the CRISPR/Cas9 system can rapidly reduce GPC and improve ECQ of rice, providing a new strategy for the breeding cultivars with desired ECQ.
基金This work was supported by the Science and Technology Innovation programme of Shenzhen Science and Technology Commission(grant number:JCYJ20151030151431727)Shenzhen Health and Population Family Planning Commission(grant number:SZLY2017012)Shenzhen Development and Reform Commission’s Stroke Screening and Prevention Public Service Platform improving programme.
文摘Prehospital delay is one of the major causes of low rate of intravenous recombinant tissue plasminogen activator(rt-PA)thrombolysis for acute ischaemic stroke in China.Regional emergency systems have been proven a successful approach to improve access to thrombolysis.Shenzhen is a high population density city with great geographical disparity of healthcare resources,leading to limited access to rt-PA thrombolysis for most patients with acute ischaemic stroke.To improve rapid access to rt-PA thrombolysis in Shenzhen,a Shenzhen stroke emergency map was implemented by Shenzhen healthcare administrations.This map comprised certification of qualified local hospitals,identification of patients with stroke,acute stroke transport protocol and maintenance of the map.We conducted a retrospective observational study to compare consecutive patients with acute stroke arriving at qualified local hospitals before and after implementation of the Shenzhen stroke emergency map.After implementation of the map,the rate of patients receiving rt-PA thrombolysis increased from 8.3%to 9.7%(p=0.003),and the rate of patients treated with endovascular thrombectomy increased from 0.9%to 1.6%(p<0.001).Sixteen of 20 hospitals have an increase in the number of patients with stroke treated with rt-PA thrombolysis.The median time between receipt of the call and arrival on the scene reduced significantly(17.0 min vs 9.0 min,p<0.001).In Shenzhen Second People's Hospital,the median onset-to-needle time and door-to-needle time were reduced(175.5 min vs 149.5 min,p=0.039;71.5 min vs 51.5 min,p<0.001).No statistically significant differences were found in the proportion of rt-PA-treated patients within various geographical distances.Currently,there are more than 40 cities in China implementing a stroke emergency map.The Shenzhen stroke emergency map improves access to rt-PA thrombolysis for acute ischaemic stroke,and the novel model has been expanded to multiple areas in China.Future efforts should be conducted to optimise the stroke emergency map.
基金National Natural Science Foundation of China,Grant/Award Numbers:81871907,81822029,81872288,82173015,81902315,81902869,81774291ShanghaiMunicipal Education Commission-Gaofeng Clinical Medicine,Grant/Award Number:20191834+5 种基金Project of Clinical Research Supporting SystemClinical Medicine First-class DisciplineShanghai Municipal Education Commission and Shanghai Education Development Foundation,Grant/Award Number:18CG16Shanghai Sailing Program,Grant/Award Number:19YF1444800Science and technology commission of Shanghai municipality project,Grant/Award Numbers:19140902600,21140902800Shanghai ChestHospital,Grant/Award Numbers:2018YNJCM01,2019YNJCM06,2021YNZYJ01,2021YNZYY01,2021YNZYY02。
文摘Background:Resistance to ferroptosis,a regulated cell death caused by irondependent excessive accumulation of lipid peroxides,has recently been linked to lung adenocarcinoma(LUAD).Intracellular antioxidant systems are required for protection against ferroptosis.The purpose of the present studywas to investigate whether and how extracellular system desensitizes LUAD cells to ferroptosis.Methods:Established human lung fibroblasts MRC-5,WI38,and human LUAD H1650,PC9,H1975,H358,A549,and H1299 cell lines,tumor and matched normal adjacent tissues of LUAD,and plasma from healthy individuals and LUAD patients were used in this study.Immunohistochemistry and immunoblotting were used to analyze protein expression,and quantitative reverse transcription-PCR was used to analyze mRNA expression.Cell viability,cell death,and the lipid reactive oxygen species generationwere measured to evaluate the responses to ferroptosis.Exosomes were observed using transmission electron microscope.The localization of arachidonic acid(AA)was detected using click chemistry labeling followed by confocal microscopy.Interactions between RNAs and proteins were detected using RNA pull-down,RNA immunoprecipitation and photoactivatable ribonucleoside-enhanced crosslinking and immunoprecipitation methods.Proteomic analysis was used to investigate RNA-regulated proteins,and metabolomic analysis was performed to analyze metabolites.Cellderived xenograft,patient-derived xenograft,cell-implanted intrapulmonary LUAD mouse models and plasma/tissue specimens from LUAD patients were used to validate the molecular mechanism.Results:Plasma exosome from LUAD patients specifically reduced lipid peroxidation and desensitized LUAD cells to ferroptosis.A potential explanation is that exosomal circRNA_101093(cir93)maintained an elevation in intracellular cir93 in LUAD to modulate AA,a poly-unsaturated fatty acid critical for ferroptosisassociated increased peroxidation in the plasma membrane.Mechanistically,cir93 interacted with and increased fatty acid-binding protei
基金supported by the National Natural Science Foundation of China (Nos. 21571157, U1604123, and 51473149)Outstanding Young Talent Research Fund of Zhengzhou University (1521320001)+1 种基金the Open Project Foundation of Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) (2017–29),Nankai UniversityOpen Project Foundation of Key Laboratory of Inorganic Synthesis and Preparation of Jilin University
文摘Metal–organic frameworks(MOFs) are of great interest as potential electrochemically active materials.However, few studies have been conducted into understanding whether control of the shape and components of MOFs can optimize their electrochemical performances due to the rational realization of their shapes. Component control of MOFs remains a significant challenge. Herein, we demonstrate a solvothermal method to realize nanostructure engineering of 2D nanoflake MOFs. The hollow structures withNi/Co-and Ni-MOF(denoted as Ni/Co-MOF nanoflakes and Ni-MOF nanoflakes) were assembled for their electrochemical performance optimizations in supercapacitors and in the oxygen reduction reaction(ORR). As a result, the Ni/CoMOF nanoflakes exhibited remarkably enhanced performance with a specific capacitance of 530.4 F g^(-1)at 0.5 A g^(-1)in1 M LiO H aqueous solution, much higher than that of NiMOF(306.8 F g^(-1)) and ZIF-67(168.3 F g^(-1)), a good rate capability, and a robust cycling performance with no capacity fading after 2000 cycles. Ni/Co-MOF nanoflakes also showed improved electrocatalytic performance for the ORR compared to Ni-MOF and ZIF-67. The present work highlights the significant role of tuning 2D nanoflake ensembles of Ni/Co-MOF in accelerating electron and charge transportation for optimizing energy storage and conversion devices.
基金supported by Funding of Jiangsu Innovation Program for Graduate Education of China (No.KYLX15_0231)Postgraduate Research & Practice Innovation Program of Jiangsu Province of China (No.KYCX17_0279)+1 种基金the Fundamental Research Funds for the Central Universities,Aviation Industry Corporation of China Technology Innovation Fund for Fundamental Research (No.2014D60931R)Funding of Ministry of Industry and Information Technology for Civil Aircraft
文摘Fuel tank inerting technologies are able to reduce the fire risk by injection of inert gas into the ullage or fuel, the former called ullage washing and the latter fuel scrubbing. The Green On-Board Inert Gas Generation System（GOBIGGS） is a novel technology based on flameless catalytic combustion, and owning to its simple structure and high inerting efficiency, it has received a lot of attentions. The inert gas in the GOBIGGS is mainly comprised of CO2, N2, and O2（hereinafter, Mixed Inert Gas（MIG））, while that in the On-Board Inert Gas Generation System（OBIGGS）, which is one of the most widely used fuel tank inerting technologies, is NitrogenEnriched Air（NEA）. The solubility of CO2 is nearly 20 times higher than that of N2 in jet fuels,so the inerting capability and performance are definitely disparate if the inert gas is selected as NEA or MIG. An inerting test bench was constructed to compare the inerting capabilities between NEA and MIG. Experimental results reveal that, if ullage washing is adopted, the variations of oxygen concentrations on the ullage and in the fuel are nearly identical no matter the inert gas is NEA or MIG. However, the ullage and dissolved oxygen concentrations of MIG scrubbing are always higher than those of NEA scrubbing.
基金supported by National Key R&D Program of China (2019YFA0110600)National Natural Science Foundation of China (81970986, 81771125)
文摘Osteoarthritis, a disorder characterized by articular cartilage deterioration, varying degrees of inflammation, and chondrocyte apoptosis, is the most common chronic joint disease. To slow or reverse its progression, inflammation should be inhibited, and chondrocyte proliferation should be promoted. Tetrahedral framework nucleic acids can be internalized by chondrocytes(even inflammatory chondrocytes) and can enhance their proliferation and migration. Wogonin, a naturally occurring flavonoid,suppresses oxidative stress and inhibits inflammation. In this study, tetrahedral framework nucleic acids were successfully selfassembled and used to load wogonin. We confirmed the effective formation of tetrahedral framework nucleic acid/wogonin complexes by dynamic light scattering, zeta potential analysis, transmission electron microscopy, and fluorescence spectrophotometry. Tetrahedral framework nucleic acids, wogonin, and especially tetrahedral framework nucleic acid/wogonin complexes effectively alleviated inflammation in vitro and in vivo and prevented cartilage destruction. In addition, these materials remarkably downregulated the expression of inflammatory mediators and matrix metalloproteinases, upregulated chondrogenic markers, and promoted tissue inhibitor of metalloproteinase 1 and B-cell lymphoma 2 expression. In vivo, after treatment with tetrahedral framework nucleic acid/wogonin complexes, the bone mineral density in regenerated tissues was much higher than that found in the untreated groups. Histologically, the complexes enhanced new tissue regeneration, significantly suppressed chondrocyte apoptosis, and promoted chondrogenic marker expression. They also inhibited cell apoptosis, increased chondrogenic marker expression, and suppressed the expression of inflammatory mediators in osteoarthritis. Therefore, we believe that tetrahedral framework nucleic acid/wogonin complexes can be used as an injectable form of therapy for osteoarthritis.
基金This work was supported by the National Key Research and Development Program of China(2016YFD0200901 and 2016YFD0200305)the Fundamental Research Funds for the Central Universities(KJQN201514 and KYZ201625)。
文摘Magnesium(Mg)affects various critical physiological and biochemical processes in higher plants,and its deficiency impedes plant growth and development.Although potassium(K)-induced Mg deficiency in agricultural production is widespread,the specific relationship of K with Mg and especially its competitive nature is poorly understood.This review summarizes current knowledge on the interactions between K and Mg with respect to their root uptake,root-to-shoot translocation and distribution in plants.Their synergistic effects on certain physiological functions are also described.The antagonistic effect of K on Mg is stronger than that of Mg on K in root absorption and transport within plants,indicating that the balanced use of K and Mg fertilizers is necessary for sustaining high plant-available Mg and alleviating K-induced Mg deficiency,especially in plant species with high K demand or in highavailable-K soil.The relationship between Mg and K in plant tissues may be antagonistic or synergistic depending on plant species,cell type,leaf age,source-and sink organs.There are synergistic effects of K and Mg on photosynthesis,carbohydrate transport and allocation,nitrogen metabolism,and turgor regulation.Definition of optimal K/Mg ratios for soils and plant tissues is desirable for maintaining proper nutritional status in plants,leading to a physiological state supporting crop production.Future research should concentrate on identifying the physiological and molecular mechanisms underlying the interactions between K and Mg in a given physiological function.
基金The authors acknowledge financial support from National Natural Science Foundation of China(Nos.81873918,51631009)Construction Project of Liaoning Medical Imaging and Interventional Medical Engineering Research Center(Grant No.18-006-9-01)Key Research and Serving Local Area Projects of the Educational Department of Liaoning Province,China(Grant No.ZF2019005).
文摘Copper is an indispensable trace metal element in the human body,which is mainly absorbed in the stomach and small intestine and excreted into the bile.Copper is an important component and catalytic agent of many enzymes and proteins in the body,so it can influence human health through multiple mechanisms.Based on the biological functions and benefits of copper,an increasing number of researchers in the field of biomaterials have focused on developing novel copper-containing biomaterials,which exhibit unique properties in protecting the cardiovascular system,promoting bone fracture healing,and exerting antibacterial effects.Copper can also be used in promoting incisional wounds healing,killing cancer cells,Positron Emission Tomography(PET)imaging,radioimmunological tracing and radiotherapy of cancer.In the present review,the biological functions of copper in the human body are presented,along with an overview of recent progress in our understanding of the biological applications and development of copper-containing materials.Furthermore,this review also provides the prospective on the challenges of those novel biomaterials for future clinical applications.
